This project has been concerned with the emergency laboratory diagnosis of acute drug overdose. To this a comprehensive analytical procedure has been developed for the systematic detection and quantification of those drugs in biological fluids which are most often involved in acute suicidal overdose. The procedure is specifically designed for 24 hour use in the general hospital clinical laboratory. An interactive computer has been written and tested for the evaluation of the analytical data. The use of a computer reduces the expertise required for interpretation of the raw data from analysis and maximizes the information obtained. The data obtained from overdose specimens has been used to study the clinical correlation of drug concentrations in plasma following overdose. Such studies of chlordiazepoxide, methyprylon and methaqualone have been completed. During the coming year the analytical system will be expanded, and the computer algorhithm modified based upon our experience with it in routine use. Studies of clinical correlation will be continued. In particular we have data from about 50 cases of diazepam overdose. In addition to studying the clinical significance of plasma levels, more specific gas chromatograph studies will be performed to determine the concentration of unchanged drug and major metabolite in plasma following overdose. This data will be compared with that derived from less specific ultraviolet procedures. The total purpose of this project has been to improve the management of patients with drug overdose by improving analytical methodology, applying a digital computer to data processing, and increasing our understanding of drug concentration and distribution following overdose.